Designing my own theme

I work for a small NGO in South Africa. They've chosen to use WordPress as their official site because it makes accessing it and posting content much easier.

I've been asked to redesign the site though, and I'm finding that the templates are all very limiting. I have experience in web design and I would like to try and develop my own theme. Does anyone know if this is possible? Could I develop a theme using HTML coding and upload it onto my WordPress account?

If you must use your own design, then you'll need to buy a domain name, and pay a company like GoDaddy, Network Solutions, and others to host your site. WordPress.ORG has free software to make your site function.

A few other notes - Themes are coded in php not html - and if you don't know what you are doing you can open up a security hole in the system big enough to drive the whole web through - so caution is advised -

If you really can't make a theme here work and decide to move then look at the 1,500 or so available at WordPress.ORG for free that have already been tested

The CSS option can be used to change the look of a theme so much that you can't recognize which theme you started with

If you are good with CSS, you can use the Tool Box theme, which is a blank canvas and has a lot of capabilities. You cannot add functionality with CSS though, such as new sidebars or anything like that. CSS is for styling an placement of page elements only.